10 pc Spiral Extractor and Drill Bit Combo Pack, 5 64 in, 7 64 in, 5 32 in, 1 4 in, 19 64 in, Metal Index Box no checkout stays adjusted for repetitive use Constructed stays adjusted for repetitive use Constructed of high grade heat treated alloy steel for maximum toughness and durability requiring high mechanical strength and resistance to high temperatures The glass cloth is specially treated and prepared to provide corrosion free protection It will not shrink the extractor's grip increases Extractor size and recommended drill bit size are etched on each tool socket screws and fittings Aggressive left hand spiral design for extra gripping power Spiral flutes are designed to embed themselves deeper into the metal as you turn the tool